Interpreting interactions from graphs

A cookbook company wants to know if food type (gourmet or not gourmet) and region (American or French) influence cookbook sales.

IV1	Food type: gourmet or not
IV2	Region: American or French
DV	Sales

Below are five different graphs of how the data could look.  For each graph, indicate whether there is a significant interaction, and if so, describe the interaction.

1)

 

 

 

 

 

 

2)

 

 

 

 

 

 

 

 

3)

 

 

 

 

 

 

 

4)

 

 

 

 

 

 

 

 

5)

 

 

 

 

 

 

 

 

Video solution to problem

slides for interpreting interactions from graphs

Answers – remember that there are many different ways to describe an interaction.  So you may not describe the interaction the exact way listed in the answers below.

1) Yes, there is an interaction.  People buy equal numbers of American and French gourmet cookbooks, equal numbers of American gourmet and not gourmet cookbooks, but do not buy as many French not gourmet cookbooks.

2) No, there is not an interaction.

3) Yes, there is an interaction.  People buy more French gourmet books and American not gourmet books, and don’t buy as many American gourmet books and French not gourmet books.

4) No, there is not an interaction.

5) Yes, there is an interaction.  People buy an equal number of American and French not gourmet cookbooks, followed by American gourmet cookbooks, and the least French gourmet cookbooks.

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